Broadcast leader & clock builder

Bars, tone, slate & countdown — timed to programme start.

Every file delivery opens with the same run-up: colour bars and line-up tone, an ident clock or slate, then black, with the first frame of action landing exactly on a fixed programme-start timecode — 10:00:00:00 for most broadcasters. Pick a spec to anchor the sheet to its real programme start, adjust the run-up, and print it for the edit — or run the live countdown clock and download the leader as an MP4.

Broadcaster spec (anchors programme start)

Programme start TC

Frame rate

Timecode	Duration	Video	Audio
09:59:30:00	20 s	100% bars (100/0/100/0)	1 kHz line-up tone @ -18 dBFS
09:59:50:00	7 s	Ident clock or slate — title, episode, duration, TC	Silence
09:59:57:00	3 s	Black DPP places an optional 2-frame sync plop (min. 50% white + 1 frame of 1 kHz tone) at 09:59:57:06, no later than 09:59:57:08.	Silence
10:00:00:00	—	Programme — first frame of action	Programme

Run-up 30 s · leader starts 09:59:30:00

Leader pattern

The modern file-delivery run-up used by ITV, BBC, Channel 4/5 and Clearcast — 20 s bars, 7 s clock, black to programme.

Segment durations

Colour bars & tones

Ident clock / slates

Blacks

Colour bars

Line-up tone level

Slate metadata (each line optional — empty removes it)

Title

Episode Number

Program Duration

Program Start

Video Format

Aspect Ratio

Audio Format

Audio Tracks (one channel per line)

Timecode calculator — add, subtract and convert SMPTE timecode.
Loudness targets & gain — line-up level and programme loudness per spec.
Safe areas & aspect ratio — where the slate text has to sit.